Slack-cable device



Em mm m Nn u y Jwl u J K d e l m Ndv. 27, 1923.

Patented Nov. 27, 1923.

UNITED STATES PATENT OFFICE.

GRIFFITH JOHN, 0F YONKERS, NETV YORK, ASSIGNOB, TO SUNDH ENGINEERING AND MACHINE COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A COBEORATION OF PENNSYLVANIA.

SLACK-CABLE DEVICE;

7 0 all whom it may concern:

Be itknown that I, GRIFFITH JOHN, a subject of the King of Great Britain, residing in Yonkers, in the county of Westchester and State of New York, have invented a new and useful Improvement in Slack Cable Devices, of which the following is a specification.

My invention relates to the class of appliances commonly known as slack cable clevices, to be used in connection with tube drawing apparatus or the like in this instance, for keeping the cables. or other flexible means taut at all times, when same are used as a drawing and return means for propelling the draw clamp or vise on the tracks of the said apparatus.

An object of the invention is to provide means whereby the drawing means of the apparatus is brought to a stop in case of emergency, such as the breaking of the cables.

Another object of the invention is to provi de simple and practical means, which will keep the cables taut at all times.

With the above objects in view, the invention consists in the apparatus hereinafter described and illustrated in the accompany ing drawing in which:

Figure 1 is a longitudinal fragmentary viewof a tube drawing apparatus embody ing the present invention.

Figure 2 is a plan view of the present invention.

Figure 3 is an elevation of Figure 2, shown partly in section.

Figure 4 is a plan view of the tube drawingapparatus showing the draw clamp and the cable equalizers.

Similar characters of reference are employed in the above described views to indicate corresponding parts.

For obvious reasons it is of the utmost importance that the cables be kept taut at all times in a tube drawing apparatus. The object of the pulling cables under working conditions is to pull the tube through a die, thus overcoming considerable resistance, they will stretch under such a strain. The return cables function to bring the draw clamp back to be in a position to draw another tube,

. after the preceding tube has been drawn.

Where both the pulling and return cables are secured atone of their ends to the draw clamp or vise, as in the present illustration,

their other ends being secured to a drum or the like, upon which they are wound, any stretching of the pulling cables resultsin a sagging of the return cables. Of course, the pulling cables may also sag, due to their own welght when extended over any great dis tance, on the return. But the said cables will be kept taut by this device even if this sagging occurs. A. tube drawing apparatus of the illustrated character, not embodying some mechanism to take up the slack in the pulling cables, will result in a jerky and um even start in the operation of drawing a tube, causing any one of many untoward difiiculties in the drawing of a tube, ail of which are known to those skilled in the art of using the said type of machine in drawing tubes. Consequently it is desirable to embody in the machine a slack cable device, usuable in connection with the pulling cables in their return as illustrated in the drawings, which device bears down on the return cables, and thus keeps the cables taut.

The slack cable device also functions to operate a switch, located underneath the free end of the device, and which switch is operated when either the pulling or return cables break, causing the device to fall upon the switch, thereby opening its contacts, same adapted to be placed in the control circuit of 1:

the driving means, such as an electric motor, causing the driving means to come to rest. The pulling cables may break if the pull in the operation of drawing a tube is greater than the cables can stand or after they have worn they may break, and the return cables may break if after they have returned. the draw mechanism to the die the power is not then cut off but is still kept on, the cables are then pulling against the die holding the draw mechanism from moving. After the draw mechanism is returned to the die and the power is still on the pulling cables will become slack and the slack cable device will operate to cut off the power before the cables can be broken. The slack cable also eliminates any tangling of the ropes that would ordinarily occur should the driving means be allowed to continue after a break in the cables occurs until stopped by the normal means for stopping the driving mechanism at the completion of drawing a tube, or in the return of the draw mechanism to the die after drawing a tube.

The slack cable device also functions to operate the switch, when the cables have stretched to such a great degree as to cause the slack cable device to bear down on the switch. Then said stretching has developed such proportion, the cables should be shortened or taken up in some other manner.

My invention, as heretofore stated, applied to tube drawing apparatus, but it is not limited to this kind of apparatus entirely, but may be used with any kind of drawing apparatus, when cables or other flexible means are used as a pulling and return means for the purpose set forth, but, as it can be as well illustrated in connection with the former apparatus, I will so describe it.

Referring to Figure 1, therein is illustrat ed, as suitable for my purpose, a fragmentary View of a tube drawing apparatus, 1, comprising a structure built up of members, 2 and 3,'t0 form a track and guide for a movable draw clamp, 4. The members are supported by legs or standards, 5, and secured at their front ends to one side of an abutment, 6, and their rear ends to standards, 7, the latter being fastened to a bed plate, 8, of a drum, 9, which is driven by a motor, 10, through the intermediation of a shaft, 11. Secured to the other side of the abutment, 6, is a tank, 12, to contain a liquid into which the tubes are dipped be fore being drawn. Recessed into the abutment is a die, 13, held in a vertical position, through which die atube drawn over a mandril, when gripped by the jaws of the draw clamp, and the said draw clamp has been caused to move by a driving mechanism. The tube and mandril are not shown in the drawing. Cables, 14, are the drawing and pulling means, one of their ends secured to the draw clamp, 4, through an equalizer, 15, as is shown in Figure 4,v and their other ends secured to thedrum, 9, and

upon which the cables are wound. A slack cable device, 22, bears down on the said cables at their drum end, so to speak, acting in the capacity heretofore set forth. Cables, 16, are the return means, and are secured at one of their ends to the draw clamp, through an equalizer, 17 as is shown in Figure 4. They then continue through a groove in the inner side of each of the members, 2 and 3, the recess in the member, 3, being indicated by the numeral, 18, the cables then extending over pulleys, 19, in the tank, 12, one of the pulleys only being seen in the drawing, a part of the tank being cut away to show the embodying of the pulley therein. The cables thence extend underneath the bench, over a pair of guide pulleys, 20, under pulleys, 21, of the slack cable device, 22, over another pair of guide pulleys, 23, and still another pair of guide pulleys, 24, on the bed plate, 8, to the drum, 9, to which they are fastened at their other ends and upon which they are adapted to be wound. The guide pulleys, 20, 23, and 24 are loosely journalled on their respective shafts, 25, 26 and 2-7, which are held by their respective bearings, 28, 29 and 30, the bearings, 2S and 29, being fastened to angle irons, 31 and 32, which are secured to the legs, 5, of the bench. The return cables are wound on the drum in the opposite direction to which the draw or pulling cables are wound. As a consequence, when the drum is rotated in a direction to wind thereon the pulling cables, it is unwinding the return cables.

The draw clamp or vise, 4, illustrated in Figure 4 is particularly adapted to be used with the type of draw bench shown, the draw bench consisting of crossheads, 33, 34 and 35. The cross heads, 33 and 34, are U-shaped with their ends turned over, thereby adapting them to bridge the member, 2 and 3, having sliding contact thereon. The crosshead, 35, is a cross-piece, and like the preceding crossheads it bridges the member 2 and 3, and also has sliding contact thereon. The crossheads are interconnected with each other through the intermediation of the other part of the draw clamp. The above brief description of the draw clamp is deemed sufficient to illustrate its embodiment with the type of draw bench shown.

Referring to Figures 2 and 3, therein are shown views of the slack cable device, 22, which comprises an I beam, 36, its fastening end being loosely journalled to the shaft, 26, by means of a bearing, 37, the bearing being secured to the under side of the I beam. To the free end of the beam is fastened a three sided plate, 38, two ofits sides being fastened to the opposite sides of the beam, the other side extending underneath it, which is adapted to make contact with a switch, 39, placed in a pit, 40, underneath the bench, into which the free end of the slack cable device extends, opening contacts, 41, of the switch, thereby opening the supply circuit to the driving means, bringing the driving means to rest. Midway or thereabouts there is fastened to the under side of the beam, 36, a bearing, 42, supporting a shaft, 43, upon which the pulleys, 21, are loosely journalled, shoulders, 44 and 45, being fastened to the ends of the shaft to prevent the pulleys from coming off.

The slack cable device 22 and 22' may be structurally similar to each other, however,

'their shaft, 43.

beam of the device, which bearing is not seen. The pulleys are loosely journalled to Shoulder, 4A, and a like shoulder on. the other side of the device are fastened to the ends of the shaft to prevent the pulleys from coming ofl'. The switch, 39, is adapted to be operated by the device, 22, in its downward movement, opening the contacts of the switch, thereby opening the supply circuit to the driving means, bringing the said means to rest.

The operation of the present invention of slack cable devices having been told hereinbefore, and its description just related, its operation need not be repeated again, as it can be readily gathered from the foregoing.

It is to be understood that I do not limit my invention to use with tube drawing apparatus or the like, since my invention may find application and be useful in other connections, and certain changes as to specific construction and arrangement of parts may be resorted to that fall within the scope of the appended claims.

Having fully described my invention, what I desire to claim and secure by Letters Patent or" the United States is:

1 In a tube drawing apparatus, the combination of a draw clamp, pulling and return cables, means to actuate the cables, an electric motor to drive the means to actuate the cables a supply circuit to the motor, and a slack cable device, adapted to be actuated by the return cable, a switch, adapted to be automatically opened by the bench and a power apparatus for operating the draw bench, a cable system, a grip device for gripping the tube to be drawn, a slack cable device, arranged to keep the cable system taut and equalizing hitches for the cables to get proper equal strain on the cables.

4:. In a tube drawing apparatus, a draw clamp, a power apparatus for operating the draw clamp, cables for drawing a tube, and other cables for returning the first said cables, means to keep both said cables taut, and means connected with the first said cables, to save the second said cables from being pulled apart.

5. In a tube drawing apparatus, a draw clamp, a power apparatus for operating the draw clamp, cables for drawing a tube, and other cables for returning the first said cables, means to keep both the said cables taut, and an electrical device connected with the first said cables, to save the second said cables from being pulled apart.

In testimony whereof, I have signed my name to this specification.

GRIFFITH JOHN. 

